Multiplying machine



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MULTIPLYING MACHINE Filed June 4, 1955 8 Sheets-Sheet 1 FIGJQ.

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ATTO EY July 11, 1939. J. M. CUNNINGHAM 2,165,230

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)u INVENTOR BY ATTORNEY J. M. CUNNINGHAM July 11, 1939.

MULTIPLYI'NG MAcmNE Filed June 4, 1955 8 Sheets-Sheet 7 )u INVENTQR MY ATTORNEY July 11, 193 J. M CUNNINGHAM MULTIPLYING MACHINE Filed June 4, 1935 8 sheets -sheet 8 h, INVENTQR MY 7 ATTORNEY Patented July '11, 1939 PATENT OFFICE 2,165,230 MULTIPLYING MACHINE James M. Cunningham, Endicott, N. Y., assignor to International Business Machines Corporation, New York, N. Y., a corporation of New York Application June 4, 1965, Serial No. 24,789

2 Claims.

The present invention relates to multiplying machines and more specifically to machines of the record card controlled type.

The principal object of the invention is to provide improvements in such machines whereby problems of greater complexity may be solved.

A more specific object of the invention is to provide means foievaluating the equations where A, B and- C areamounts derived from a record card and to enter the result back on the card. i

A further object of the invention is to provide means for testing the resulting value todetermine whether it is in the form of a true number, a complement, or zero and to control the subsequent operation of the machine accordingly.

A further object of the invention is to provide means for entering a so-called elusive one into the units order of an accumulator in advance of the entry of a nines complement therein.

A still further object resides in the provision of a plurality of successive elusive one entries into an accumulator equal in number to a predetermined number of subsequent nines complement entries.

A further object resides in the provision of switching devices whereby the machine may be readily converted from a standard multiplying machine to one capable of performing special computations involving the solution of equations.

Various other objects and advantages of the invention will be obvious from the following particular description of one form of mechanism embodying the invention or from an inspection of the accompanying drawings; and the inven'-- tion also-constitutes certain new and useful features of construction and combination of parts hereinafter set forth and claimed.

In the drawings:

Figs. 1a, 1b, and 1c, taken together and placed one above the other in the order named, constitute a wiring diagram of the electric circuits of the machine.

Fig. 2 is a diagrammatic representation of the various units of the machine showing the manner in which they are interconnected for the computation of equations of the form Fig. 3 is a similar diagram showing the connections for the computations of equations of the form [A+(C' B)]-C' and [A(CXB)]-C.

Figs. 4a and 4b, taken together, represent a timing diagram of the essential circuit controlling elements of the machine.

Standard operation Before explaining the manner in which the mahine operates in the computation of the various equations outlined in Figs. 2 and 3, a brief explanation will be given of the manner in which the machine operates in performing simple multiplying operations. The mechanical structure of the machine is substantially the same as that of Patent No. 1,933,714, granted November 7 1933 20 to J. M. Cunningham, and in Patent No. 1,944,665, granted January 23, 1934, to D. J. Oldenboom.

After the record cards bearing perforations representative of the factors to be multiplied have been placed in the feed magazine of the ma- 25 chine and after the various preliminary plug connections have been made for directing the entries into the accumulators, the main line switch SW (Fig. 1c) is closed, which places the motor M in operation. The motor M drives the -ACDC generator, indicated at A0 and DC,

Figs. 1a and 10, respectively. The DCportion of the generator supplies current to DC lines l0 and, II (Fig. 1c) and the AC commutator supplies current to ground and to a line 12. The 35 start key contacts l3 (Fig. 1c) are now closed by depression of the start key button, which completes a circuit from the DC line I0, through a relay coil C, contacts l3 (now closed) (I96 of Patent 1,944,665), upper contacts GI, cam con- 40 tacts FC2, to line II. The coil C establishes a holding circuit through'its contacts C2 and cam contacts FC8.

The coil C, when energized, also closes a pair of contacts C I which will complete a circuit from line l0, normally closed relay contacts Fl, card feed clutch magnet I4 (222 of Patent 1,944,665) cam contacts FC6, stop key contacts 15 (I91 of Patent 1,944,665), relay contacts NI, contacts Cl, a pair of contacts l6 (P-1 of Patent 1,944,665), to line ll.

Energization of card feed clutch magnet I will cause withdrawal of a card from the magazine and will advance it to the analyzing brushes I! (Fig. 1a).- During this movement of the card, 5

the usual card lever is engaged to close card lever contacts I8 (Fig. 1c) (112 of Patent 1,944,665) which complete a circuit from line H, contacts l3, relay magnet H, to line III.

In starting up the machine, it is necessary to hold down the start key to maintain the contacts I3 closed during the first complete card feeding cycle, or alternatively, to depress the start key a second time. At the beginning of the second card cycle the closure of cam contacts FCH will energize relay magnet G through a circuit including card lever contacts l3. Relay magnet G will close its normally open contacts GI, setting up a holding circuit through cam contacts F02 and will also close relay contacts G2 to provide a further holding circuit through the card lever contacts it. These two holding circuits alternate in maintaining relay magnet G energized as long as cards continue to feed from the maga zine. The relay magnet H is also provided with a holding circuit which extends through card lever contacts l8 or serially through relay contacts G2 and cam contacts FC2.

Energization of relay magnet H will cause shifting of its contacts Hi (Fig. 1a) to the reverse of the position shown, thereby supplying current to the impulse distributor I9 (188 of Patent 1,944,665) which supplies current through contacts FC'I (closed in the first half of the card feed cycle) to the analyzing brushes i1 and as the card proceeds past the analyzing brushes, circuits will .be completed to theaccumulators selected to receive entries in accordance with the perforations in the record card; that is, as the card traverses the brushes H, the multiplier factor will be entered into the multiplier accumulator and the multiplicand factor will be entered into the multiplicand accumulator.

The entering circuits extend from the AC generator, through line l2, to the now closed contacts Hi, cam contacts FCI, distributor l9, brush contact roll between which and the brushes I! the card passes. From the contact roll the circuits extend through the perforations in the card, the

brushes H, to plug sockets 23, from which suit-- able plug connections are made to sockets 2| and sockets 22 of the multiplier and multiplicand accumulators, respectively, to effect energization of the adding magnets .23 (213 of Patent 1,944,665) of the related accumulators. The entering circuit, afterpassing through the magnets 23, continues through normally closed contacts A2 to ground.

After the first card has traversed the brushes i'l it is fed into the punching unit of the machine and upon its arrival there, it causes closure of punch card lever contacts 24 of Patent 1,944,665) (Fig. 10) which cause energization of the relay magnet F. The closure of the normally open contacts Fl establishes a circuit fromline l0, through now closed contacts Fl, cam contacts CO3, trip magnet 25 (143 of Patent 1,944,665) of the punching unitwhich functions to trip clutch mechanism to further advance the card to punching position. The circuit continues through eject contacts 26 (P--3 of Patent 1,944,665) and relay contacts Kl which at this time are in the position reverse 'to that shown. The contacts Kl are controlled-by relay magnet K which is energized through last column contacts 21 (P5 of Patent 1,944,665) in the punching unit. These so-called last column contacts close whenever the' card advancing carriage of the punching entire machine is first started so that upon starting, relay K is energized and its contacts Kl are in shifted position.

The cards are handled in the card punching unit in the customary manner as set forth in the above mentioned patents. After the analyzed card has been advanced column by column in the punching unit and the left hand component accumulator LH is being reset, a circuit is completed which extends from line I I (Fig. 1c) upper contacts 44 (129 of Patent 1,944,665), 80 operated similarly to contacts 44 and 19 which are closed while the LH accumulator is resetting, switch TF2 (in dotted line position), wire 23 (Figs. 1b and 1a), through relay magnets M and N in parallel, wire 29 (Figs. 1b and 1c), to line l0. Relay magnet M closes its contacts M2 (Fig. 1a) to provide a holding circuit for the relays extending from line l0, wire 29, relays M and N, contacts M2, wire 30, to the normally closed contacts 3| of Patent 1,944,665) (Fig. 1c) and line H. Contacts 3| are opened during the operation wherein the MC accumulator is reset and until such time, relay magnets M and N will remain energized. These are the master relay magnets of the cycle controller unit and they call the cycle controller into operation to determine the location of significant figures in the multiplier. The circuit through wire 28 also extends to the zero segments of the readout unit of the multiplier accumulator designated MPRO. If any of the brushes of the MPRO stand at zero, selected ones of the column skip magnets 32 will be energized according to which denominational orders of the multiplier contain zeros. The magnets 32 control contacts 3201. through which circuits are completed to the column shift relay magnets 33 and to the multiplying relay magnets 34. The magnets 32 and 33 correspond to the-magnets designated Y and CS in the Cunningham patent referred to.

In those positions in which the multiplier digit is zero, the associated magnet 32 will be energized and the related contacts 32a (Yu, Yt, etc. of Patent 1,944,665) will be shifted from the position shown in the diagram so that the related magnet 33 will 'be disconnected from the circuit which is traceable from line l2, cam contacts CCZ, relay contacts Ml, normally closed contacts 32a, relay magnet 33 through the appropriate readout spot in one order of the readout section MPRO, to the corresponding relay magnet 34 (XI, X2, etc. of Patent 1,944,665) and thence to ground. The function of the contacts 32a is to direct the multiplier relay selecting circuits through only those positions in which significant figures occur in the multiplier and to skip the positions in which 'zeros occur. With a particular magnet 34' energized, for example the X5 magnet 34, the related contacts shown in the center of Fig. 1a will become closed and with the emitter 35 (I35 of Patent. 1,944,665) in constant operation, impulses will be emitted through the contacts of the X5 multiplier relay 34 and thence through the readout device of the multiplicand accumulator designated MCRO and there-v after through the column shift relay contacts CSL and CSR (Fig. 1b) to the adding magnets 23 of the RH and LEA accumulators which thus receive the right and left hand partial product entries. The CSL and CSR relay contacts are controlled by the relay magnets 33 and serve to effect the proper denominational allocation of the partial product entries. Thus, when multiplying is being efl'ected by the units digit of the multiplier, the units magnet 33 energized and of Patent 1,944,665).

the units order set of contacts CSL and 083. are closed.

Energization of a relay magnet 33 (Fig. 141) will also close a pair of contacts 33b (CSu3, CS -3, etc. of Patent 1,944,665) which will cause energization of the relay magnet 32 in the order in which multiplying is takingplace. This in turn will shift the related pair of contacts 32a so that when cam contacts 002 again close, the aforetraced circuit will be directed through the magnet 33 in the order containing the next higher significant figure and will skip the magnets 33 in positions in which zeros are present.

The machine continues multiplying operations during which the partial products are entered in succession into the LHA and RH accumulators. After multiplying cycles have been effected for all significant multiplier digits, all of the magnets 32 will have been energized and all of the contacts 32a will be in their shifted positions so that on the next following cycle the closure of cam contacts CC2 will complete the circuit which extends through all of the now closed contacts 32a to the relay magnet 36 (ICR of Patent 1,944,665) and the multiplicand reset magnet 3'IMC (223MC A parallel circuit also extendsthrough cam contacts FClfl and multiplier reset magnet 3'IM1 (223M? of Patent 1,944,665). If switch 33 is open, the multiplier accumulator will not be reset and the factor therein will become a so-called fixed multiplier for succeeding multiplying operations. The relay magnet 36 closes its contacts 36a (Fig. 1b) "hich connect the readout section of the RH accumulator,

' designated RHRO, to'the adding magnets 23 of the LHA accumulator, thus transferring the sum of the righthand partial products into the LHA accumulator to produce the complete product. These circuits are controlled from the emitter 35 through a group of wires generally designated 39 which extend to the readout device RHRO.

In Fig. 7 is shown a section of an accumulator toillustrate the mechanical arrangement of the readout section which is the same for all the accumulators except in the number of commutator segments provided. For each order there are commutator segments Hill which are electrically connected through the brush structure IM to the common arcuate conducting strip I02. The position of the brush corresponds to the value entered on.its associated accumulator and connects the segment I00 having such value to strip I02. In the circuit diagram the segments and strips are represented as circles and vertical bars respectively.

During the cycle in which the MC accumulator is reset concurrently with the RH to LH transfer operation, the normally closed contacts 3| (Fig. 10) which are operated by a cam on the MC reset shaft will open to interrupt the circuit to the cycle controlling relay magnets 32, thus causing deenergization of all these magnets'and the interruption of their related circuits.

The RH to Llitransfer relay magnet 36 closes a pair of contacts 36b (Fig. 1a)- (lCR--l1 of Patent 1,944,665) through which a circuit is completed by the emitter after the amount in the RH accumulator has been transferred to the LHA accumulator. This circuit is traceable from line l2 through emitter 35,- which, when the brushes are at the zero segment, will continue through contacts 36b to the reset magnetsflRH (223RH of Patent 1,944,665) which. function to initiate resetting 'of this accumulator.

' mulator.

Referring now to Fig. 1c, the contacts 40 are closed along with the shifting of contacts 3| when the MC accumulator is resetting, thereby completing a circuit from line H, contacts 40, switch .TPI in dotted position, relay magnet C, to line l0. Relay magnet C establishes a holding circuit through contacts C2 as before and also closes contacts CI to complete the circuit through the card feedclutch magnet l4 as traced above. This causes the next card to be fed to the analyzing brushes where the new factors will be entered into the accumulators and in the case of fixed multiplier operation, wherein the multiplier ac- I cumulator is not reset, only a multiplicand facto line H). The plug socket T43 is of the split socket type, which, when no plug is inserted, forms a connection between relay B and cam contacts C04. The insertion of a plug will split the socket permitting connection between plug connection 42 and relay magnet B and at the same time breaking the connection between magnet B and contacts-CO4. Energization of magnet B will close its contacts B2 to provide a holding circuit through normally closed contacts 44 associated with the reset devices of the LHB accu- The magnet B will also close its contacts BI, thereby establishing a circuit from line ll, contacts BI, contacts 45 (I54 of Patent 1,944,665) in the punching unit, switch 46, wire 41 (Fig. 1b) to the common conducting strip 48 (N3 of Patent 1,933,714) of the punch column selector. I v

The strip 48 is connected in succession to the segments 49 (612 ofPatent 1,933,714) as the record card moves step by step past the column of punches in the punchingiunit and'in those columns which are plug connected to the readout device LHARO will complete circuits from segments 49 to sockets 50, thence through plugconnections to sockets 5| and through the LHARO device to wires '52 which extend to the punch selecting magnets 53 (192 of Patent 1,933,714) whose common return wire 54 extends to line l0.

While the step by step punching of the product takes place in the card, the new factors are entered into their appropriate accumulators and when the card is completely punched and advanced to its last column position, relay K will be energized as before 'to closeits normally open contacts KI and complete a circuit through the eject magnet 55 (HI of Patent 1,944,665) which ejects the punched record from the machine. As explained in the above mentioned patents, the

energization of any of the magnets 53 will adcolumn. The feeding of the new card to" the brushes will again cause closure of the card lever contacts l8, causing energization of magnet H to permit the impulse distributor I9 to supply current to the card analyzing brushes IT. The machine is arranged to permit so-called group multiplication in which the multiplication of a multiplicand factor is effected by a common multiimprovements incorporated in such machines.

whereby the additional problems mentioned heretofore may be handled will now be described in connection with the circuit diagram and the diagrammatic representations in Figs. 2 and 3.

- Each of the four problems is capable of solution mulator through plug connections represented.

by the machine and each requires a slightly different arrangement of plugging connections. They will therefore be dealt with separately. For the solution of these problems switches TPI to TP'! are shifted to their full line positions as indicated on the circuit diagram.

Referring to Fig. 2, record cards bearing perforated data in fields A, B, and C are placed in the feed magazine of the machine and it is desired to compute the product AXE, the sum A+(A B), and the difference C[A+(A, B)] and to punch the results obtained back in other fields of the record card. The sockets 20 associated with the brushes I! which read the amount B are connected to sockets 2| on the MP accuby the line 60.

It may be mentioned at this point in connection with Fig. 2 that the heavy solid lines represent plug connections between the brushes and the accumulators and the heavy dotted lines represent plug connections between the punches and the readout devices of the accumulators, and the lighter solid lines represent fixed wiring in v I the machine.

The plug sockets 20 associated with the field in which the A amount is punched are connected to sockets 22 in the MC accumulator through plug connections SI and also through plug connections 62 to plug sockets 63 which are wired to'normally closed relay contacts CLAI and through normally closed contacts CLCI, .to the entry devices of the LHB accumulator. Sockets 20 associated with the brushes which sense the C amount are-connected through connections 64 to sockets 65 which are wired to normally closed contacts CLBI extending, through'entering devices of thev five lowest order positions of the SP accumulator and through parallel connections 66 are entered in duplicate in the five highest orders of the SP accumulator.

As the record card passes the analyzing brushes, entries are made into the MP, MC,LHB and SP accumulators, as indicated, through the connections just traced. There-after, multiplying operations ensue in the same manner as ex- Dlained in connection with the standard operation of the multiplying machine.

-during standard multiplying operations.

The M and N relays are initially energized through a different circuit than when normal multiplying is performed. The circuit is completed during the initial part of card feeding cycles by closure of cam contacts FC and is traceable from line H (Fig. 10), card lever con tacts l8, cam contacts FCH, switch TP2 (now in full line position), wire 28 to relay magnets M and N and to other side, of line as before.

The entries in the MC and MP accumulators are read out to determine the partial products which are thereafter entered through the CSL and CSR devices into the RH and LHA accumulators through the lines indicated at 61 and 68, respectively. Thereafter, the amount standing in the RH accumulator is transferred to the LH accumulator through the line designated 69 so that at this point the LHA accumulator contains the product of A and B. Thus far the operation of the machine is substantially the same as explained under the standard operation, and for the specific problem illustrated in Fig. 2 where A is 150 and B is .00082, the product will be .1230000. In carrying'the problem out further, it is not desired to consider the decimal product beyond the second place so that in the further steps of the problem, the figures to the right of the second decimal place are ignored.

There now ensues a transfer cycle of operations during which the amounts standing on the five highest orders of the LHA accumulator are transferred to the LHB accumulator and for this purpose contacts CLAI are shifted so that the entries may follow through the line designated III in Fig. 2. The controlling magnet CLA for these contacts is shown in Fig. 1c and is energized upon closure of contacts 40 associated with the MC accumulator reset devices, the circuit being traceable from line H, contacts 40, switch TF5, relay coil CLA, to line I 0.. The coil will close its contacts CLAN) to provide a holding circuit extending through contacts CLAN, 001, the contacts D2, now closed, contacts CLA9 to line H.

A second circuit is closed when lower contacts 3| make, which energizes the relay magnet D whose contacts D2 provide a holding circuit through contacts CCI and CLAS. The contacts CC serve to hold the relays CLA and D energized for a period sufficient to enter the transferred amount into the LHB accumulator. The contacts CLAI are shown in the center of Fig. 1b

and are connected through the wires 10 to the tacts DI in the center of Fig. 1b and the relay" magnet CLA closes a pair of contacts CLAI, .per-. mitting a circuit to extend from line l2, through contacts DLCLAI, switch TF9, to emitter II,

.which is connected to the readout devices of the accumulators through wires 12 in true number relationship; that'is, the 9 spot of the emitter is connected to all the 9" commutator segments of the readout devices, the "8 spots to all the 8segments, and so on, so that the amount standing. in the LHARO device will be transferred in true form to the LHB accumulator in the same manner as amounts are transferred from the RH accumulator to the LHA accumulator Following this entry cycle, there will be contained in the 'LHB accumulator the amount A plus the product (A -X B). This is now to be subtracted from the amount in the SP accumulator or, as subtraction is customarily performed in tabulating machines, added thereto in the form of a complement.

Referring to Fig. 2, this transfer operation is diagrammatically represented as extending from the LHBRO device, throughwire I3 during the passage through which the amount read out is inverted. In order to complete entry into the SP accumulator, contacts CLBI must be shifted from the position indicated. The manner in which this is effected is as follows: With contacts CLAB closed, the closure of contacts 005 will complete a circuit from line I I, contacts CO5, CLAB, switch TP8, relay magnet CLB, to line H]. Relay CLB will close its contacts CLB8, providing a holding circuit therefor through contacts C08 so that during the next cycle, when relay magnet CLA is deenergized, magnet CLB will remain energized. The shifting of contacts CLBI, which are shown in Fig. lb, will serve to connect the adding magnets 23 of the six lowest orders of the SP accumulator to the six readout positions of the LHBRO device through the wires 13. Relay coil CLB closes a pair of contacts CLB'I (Fig. 1b) so that on the next cycle with contacts DI also closed, a circuit will be traceable from line l2, through contacts DI, contacts CLBI, to emitter 14. This emitter is also known as an inverter in that the commutator spots thereon are; connected to the wires 12 in the nines complementary relationship, whichcauses the number standing in the accumulator to be read out as the nines complement thereof; thus an 8 standing in the accumulator will be transferred to the SP accumulator as a 1; a-7 as a 2, and so on.

The same entry is also made in the five highest orders of the SP accumulator through wires 66 (Fig. 1b).

During the initial card feeding and analyzing cycle, the "elusive one is entered into the units order of the SP accumulator to complement the same to ten. This is effected by the SP carry magnet 15 (Figs. 1c and 6) which, if a plug connection I6 be made between sockets 4| and 18, will be energized through a circuit extending from line II, card lever contacts l8,'switch TPB, cam contacts F04 (closed during the card feed cycle, see Fig. 4b) plug socket 4|, connection 16, socket l8, carry magnet 15, to line l0.

- For the example selected in Fig. 2, the SP accumulator will thus receive the following entries in order.

It will be noted that the elusive one in the left hand total is taken care of through a carrying operation from the sixth order to the seventh.

If the amount standing in the LHBRO device had been equal to the amount standing in the SP accumulator, the resulting summation would be as follows:

00000 00000 The entire accumulator would thus cancel out to zero. If the amount in the LHBRO device were greater than the SP entry, the resulting summation would be as follows, assuming the LHBRO amount to be 55000:

Card entry 50000 50000 Elusive one entry 1 Complement transferred 44999 9 44999 In this case there is no carry from the sixth to the seventh order and the six lowest orders represent the complement of the credit balance.

In Fig. 5 there is represented diagrammatically the readout section of the seven highest orders of the SP accumulator, the remaining orders being the same as the two shown at the right end of the figure. In the five highest positions only zero segments Hill are provided and in the next adjacent position only the 9 segment Hill is required. The 9 segment is tested as will be explained to ascertain the presence of a result in complementaryform and the zero segments are tested to determine the presence of a zero balance.

In accordance with the problem of Fig. 2 the SP' accumulator contains a true balance in duplicate, this being the result of the evaluation of the Equation 0- [A+(A B)] and the machine is now ready to punch this amount back in the card as 349.88.

During the cycle in which relay coil CLB is energized, the closure of cam contacts C06 will complete a circuit from line I I, earn contacts CO6, contacts CLBQ, relay magnet S, which closes its contacts S2 to provide a holding circuit through normally closedcontacts 44 associated with the LHB reset devices. Relay magnet S closes its contacts SI which will permit energization of relay magnet B when cam contacts C04 close, the circuit extending from line H, contacts SI, 0C4, to relay B and line I0.

Relay magnet B closes its contacts B2 to provide a holding circuit and by closing its contacts BI at the top of Fig. 10 will permit the step-bystep operation of the punch in response to the readings in the several accumulators which have previously been appropriately connected to the columns of the record in which punching is desired.

After punching has been completed and the card advanced to the last column position, closing contacts 21 at the bottom of Fig. 1c, relay K will be energized, closing its contacts K2 at the top of Fig. 1a so that a circuit may be completed upon closure of cam contacts 002 which is traceable from line I2, through contacts (1C2, contacts K2, normally closed contacts L2, switch TF3, to the reset magnets 31LI-I which function to control resetting of the LHA and LHB accumulators. A further circuit extends from switch TP3 to switch 'I'PI to the summary accumulator reset magnet 3'ISP so that this accumulator is reset concurrently with the LH accumulators. Resetting 01 the LH acciunulators is accompanied by a closure of contacts 19, 80 and upper contacts 44 all shown in the center of Fig. 1c whereby a circuit is traceable from line H, upper contacts 44, contactsflll, contacts I9, wire 8|, switch TPI, relay magnet C, to line l0. As before, energization of relay magnet C causes feeding of a new card to the analyzing brushes in readiness for repetition of the cycle of operations under control of perforations in the new record card.

As explained above, the entries in the SP accu'nulator are made in duplicate, one set in the right hand section and the other set in the left hand section. The accumulation of the right hand section is for the purpose of controlling punching and the total standing in the left hand section is sensed to determine the status of the new balance as computed and controls the perforation of special designations in a predetermined column of the card, for example, the 79th column, in accordance with the determined status of this new balance. Specifically, if the new balance is a positive number, a 1" will be punched in column 79. If the new balance is a complement, the record card will be ejected from the machine without punching and if the new balance is zero, indicating that the payment plus the interest amount has equalled the amount of the original loan, a zero is punched in column 79.

The two sections of the SP readout device are separately designated as' SARO and SBRO in they lower left hand corner of Fig. 1b and in Fig. 5. Associated with the SPRO device are two plug sockets 82 and 83, the former of which is plug connected as by a connection 84 (see Fig. 2) to the plug socket 58 associated with the 79thcolumn of the card. The socket 82 is wired to contacts Ri of a relay magnet R and the normally closed blade of the contact is connected to the 1 punch selecting magnet while the normally open blade is connected to the zero selecting magnet so that when the 79th column of the card is in punching position, a circuit will be completed through either the 1 or punch selecting magnets 53 accordingly as the relay contacts RI remain in the position shown or are shifted.

If the reading in the SPRO device is zero in all orders, a circuit will be traceable through the device as follows: from line l8 (Fig. 1c), relay magnet R, wire 85 (Fig. 1b) to the commutator strip I82.in.the lowest order of the SBRO device ,(see also Fig. thence serially through the commutator brushes l8i standing at zero, their associated segments I88 and commutator strips |82.and connections 88 to wire 88 (Fig. 1c) contacts B2, lower contacts 44, to line H. Relay magnet R will shift its contacts RI thus connecting the zero punch selecting magnet 53 to the socket 82 so that a zero will he punched in the 79th column of the card. If all five positions of the SBRO device do not register zero,the series circuit traced will not be completed and the 1" selecting magnet 53 will remain connected to the socket 82 and a 1 will be punched in the 79th column unless, as will be explained presently, the amount is in the form of 'a complement.

The highest order of theSARO device is tested to determine if the final result is a complement and if this highest order stands at "9", it is an indication that such is the case. The readout strip I82 of the highest order of the SARO device is connected through a wire 89 to relay magnet E and a circuit is traceable from line l8, relay coil E, wire 89 (Fig. 1b), strip I82 (see also Figs 5), the 9" commutator segment I88 and brush l8! in the corresponding order, wire 88 (Fig. 1c) cam contacts CO9, relay contacts SI, which are now closed, to line H. Relay magnet E closes its contacts E2 to provide a holding circuit through the normally closed contacts Kl.

Energization of relay magnet E will shift its contacts El atthe top of Fig 1c, so that with switch 48 in its dotted line position, the punch magnet selecting circuits, which normally pass through wire 41, will be interrupted and a circuit will be made directly from line H, through contacts BI, 45, switch 46, lower contacts El, new

closed, punch magnet 51, to line M. In the operation of the punch magnet 51, the card is advanced one step and contacts 45 are momentarily opened. Upon reclosure, the punch magnet is again energized and the card advanced a further step. In this manner, the entire card is advanced in a step-by-step manner through the punching unit of the machine without receiving any punching. Upon arriving at the last column position, it is ejected in the usual manner and resumption of the operation of the machine takes place as before.

Briefly summarizing, if the final result of the computation C-[A+(B C')], called the new debit balance is a true number, a "one will be punched in column 79. If theresult is a complementary number indicating a credit balance, the card, is ejected with all punching suppressed and if the result is zero, a zero will be punched in the 79th oclumn.

PROBLEM rate B is read into the MP accumulator. A plug,

connection 92 is made from socket 83 to socket 58 associated with the 79th column as indicated in Fig. 3.

After the various amounts have been entered into the accumulators multiplying takes placeas during the first run and the amount C is multiplied by the amount B producing the product C'XB in the LHA accumulator. Relay CLA is energized in the same manner as before to close its normally open contacts CLAI so that the product CXB is transferred additively to .accumulator LHB so that it now contains the value A+(C B).

From this amount there is now to be subtracted the amoimt C standing in the SP accumulator. In Fig. 3 this transfer operation is diagrammatically represented as extending from the SPRO device through wire 93 during the passage through which the amount read out is inverted. To complete the entry, contacts CLCI 'must be shifted from the position shown. This-is effected due to the shifting of switch TF8 in Fig. 10 so that the circuit, traced above through,

relay CLB now goes through relay CLC and is held through its contacts CLC8. The contacts CLCI in parallel with contacts CLBI supply current to inverting emitter I4 and circuits are completed to the SPRO device through wires 93, contacts CLCI, to adding magnets 23 of the LHB accumulator.

'To complete the complement the carry magnet 94 (Fig. 1c) (similar to SP car-ry magnet 15) of the LHB accumulator is energized to add the "elusive one" to the units order. To do this a plug connection is inserted between socket ll and socket 95 so that during the card feeding cycle as before, the LHB carry magnet receives an impulse to enter a one" in the units order.

. In this manner the final result obtains in the LHB accumulator and from this point on punching operations take place in the same manner as wire 54, 2 punch selecting magnet 53 (Fig. 1b),

wire 96, socket 83, connection 92 (indicated in Fig. 3) to socket of column 79 and thence to other side of line in the familiar manner. The

f2 thus punched is indicative of the credit balance.

The first run described above is known as the debit balance run before maturity and the second run as the credit balance run before maturity." A third run may be made which is called the debit balance run after maturity which is the same as thefirst run in all respects except for the manner of transferring the product from the LHA accumulator to the LHB accumulator. For this third run the transferred amount is in the form of a complement so that the final result is expressed as C'[A-(A B) The differences reside in shifting switch TF9 (Fig. 1b) to its dotted line position so that the circuit for transferring the product is to the inverting emitter 14 instead of to the true emitter H.

Sockets II and (Fig. 1c) are connected and sockets 11 and 18 are also connected to enter elusive ones in both the LHB and SP accumulators.

The fourth run, called the credit balance run after maturity is made with cards rejected during the third run and is exactly similar to the second run except for the change in sign within the brackets of the result [A-(CXB) 1-0. Here also switch TP9 is in its dotted line position for complementary transfer. Sockets 4| and 95 are plug connected and socket 11 and a second socket 95 are also plug connected. The LHB accumulator in this wise receives two elusive one carry impulses in successive cycles during card feeding operations, one from the F04 cam and the .second from the FC|3 cam (see the timing diagram) Thus when the amounts from the LHA and SP accumulators are entered in the form of complements, there will already be an entry of 2 in the LHB accumulator in the units order.

In Fig. 1c are shown contacts designated P2 (corresponding to P2 of Patent 1,944,665) which, when open, interrupt the circuits through contacts J I and LI of relay magnets J and L.

While there has been shown and described and pointed out the fundamental novel features of the invention as applied to a single modificationpit will be understood that various omissions and substitutions and changes in the form and details'of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention. It is the intention therefore to be limited only as indicated by the scope of the following claifns.

What is claimed is as follows:

1. In a machine of the class described, three accumulators, means for entering an amount in each, means for transferring the amounts in each of two of said accumulators in succession to the third in the form of nines complements settable means and means controlled by said settable means and operative in advance of said transferring for entering two elusive ones into said third accumulator.

2. In a machine of the class described, a plurality of accumulators, means for entering an amount in each, means for transferring to one of said accumulators, in succession, and in the form of nines complements, the amounts ineach of the other of said plurality of accumulators, settable means and means controlled by said settable means and operative in advance of said transferring for entering into said one accumulator a number of units equal to the number of nines complements to be transferred thereto.

JAMES M. CUNNINGHAM. 

